Fluid pressure actuated stabilizer for motor vehicles



June'9, 1959 E. B. HUDSON 2,890,064

FLUID PREssums ACTUATED STABILIZER FOR MOTOR VEHICLES Filed Maron 1,1957 'I 2 sheets-sheet 1 X24 l INVENTOR.

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E. B. HUDSON June 9, 1959 FLUID PRESSURE ACTUATED STABILIZER FOR MOTORVEHICLES 2 Sheets-Sheet 2 Fled March l, 1957 INVENTOR.

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nitecl States Patent C FLUID PRESSURE ACTUATED STABILI'ZER FOR MOTORVEHICLES Edwin B. Hudson, Middletown, Ohio Application March 1, 1957,serial" No. 643,424

9 claims. (Cl. 28o- 112) the front wheel suspension allows each frontwheel to rise and fall, due to changes in road surface level, withoutappreciably alecting the opposite wheel so long as the vehicle istraveling in a straight path. However, when the vehicle is traveling ina curved path, the outside front wheel suspension spring is compressedto a greater degree than is the inside wheel suspension spring. Forexample, when the vehicle is traveling in a curved path to the left, theright front of the vehicle body is lower than the left front and thevehicle appears to be banking to the outside of the curve. Thiscondition is known as cornering, and when observed at higher speeds thevehicle is said to not corner well. While heretofore numerous attemptshave been made to solve the cornering problem by providing various typesof mechanical and hydraulic stabilizing devices elective to prevent orminimize outside banking of the vehicle body, such devices are generallyconnected between the sprung and unsprung parts of the running gear andhence in whole or in part bypass the spring suspension when in use.

A principal object of my invention is the provision of stabilizing meanswhich will automatically correct for undesirable cornering of thevehicle while at the same time retaining full advantage of the normalsuspension springs. With my invention the vehicle is fully sprung at alltimes and there is no direct mechanical connection between the sprungand unsprung portions of the running gear excepting as occur through thesuspension springs themselves.

A further obj-ect of my invention is to provide automatic correction forcornering by compensating for the extra deection on the front outsidespring suspension without any corresponding correction to the insidespring suspension.

A further object of my invention is the provision of a stabilizingsystem which may be sensed and controlled by the conventional hydraulicsteering equipment of the vehicle. Thus, in accordance with myinvention, the banking control can be made a slave to the hydraulicsteering system.

Still a further object of my invention is to provide an alternate meanshaving a self-contained hydraulic system for sensing and controlling thestabilizing devices which is mechanically operated by the hydraulicsteering device. Such self-contained hydraulic system may bemechanically connected to the hydraulic assist cylinder ofthe steeringdevice. This arrangement has the advantage that the lluid supply doesnot have to be proportioned between the steering assist cylinder and thesuspension hydraulic cylinders.

Yet a further object of my invention is the provision of automaticallyoperated stabilizing means which are of relatively simple and economicalconstruction and which, as already indicated, can be utilized invehicles incorporating conventional spring suspensions.

The foregoing, together with other objects of my invention which'willappear herenafter or which will be understood by those skilled in theart upon reading these specifications, I accomplish by thoseconstructions and arrangements of parts of which I shall now describecertain exemplary embodiments.

Reference is made to the accompanying drawings wherein:

Figure 1 is aside elevational view With parts in section illustrating aconventional knee action construction to which the compensatinghydraulic cylinder and piston arrangement of my invention has beenadded. The ligure illustrates the parts as they appear when the vehicleis traveling in a straight path.

Figure 2 is a side elevational view similar to Figure l but illustratingthe position of the parts when the vehicle is in a turn, the runninggear illustrated being that which is to the outside of the turn.

Figure 3 is a diagrammatic illustration of an independent hydrauliccontrol system for the stabilizers, the right hand portion of the figurealso serving to illustrate the mechanical connection of the controlsystem to the hydraulic assist-cylinder of a hydraulic steering device.

Figure 4 is a diagrammatic view illustrating the application of myinvention to a conventional hydraulic steermg system.

Referring first to Figures l and 2 of the drawings, I have thereinillustrated a vehicle frame 1 which pivotally mounts lower armV 2 andupper arm 3 of the running gear, the free ends of the arms beingpivotally connected to the opposite ends .of steering knuckle 4 to whichthe wheel assembly 5 is mounted. A suspension spring 6 extends betweenthe frame 1 and a spring retaining plate 7 carried by the lower arm ofthe running gear. At its upper end the suspension spring 6 seats againstthe anged lower end 8 of piston 9 fitted in bore 10 of hydrauliccylinder 11. 'Ihe cylinder 11 is xedly secured to the frame 1 and ispositioned to overlie the suspension spring 6. Fluid under pressure isintroduced into Athe upper end of the cylinder through conduit 12, theiluid entering the bore `10 between the upper end of the cylinder andthe piston 9, thereby causing the piston to move relative to thecylinder.

When the vehicle is traveling in a straight path the pistons 9 will bein retracted position, which is the position illustrated in Figure l,with the flanged lower ends 8 seated against the bumpers 13 secured tothe frame 1. The hydraulic liuid in conduit 12 will be at zero pressure,and it will be apparent that the suspension spring 6 will serve tospring the vehicle in conventional manner. If desired, a shock absorber14 may be utilized, the shock absorber being secured at its lower end tothe plate 7 and at its upperrend to the piston 9.

Figure 2 illustrates the outside wheel suspension when the vehicle is ina turn. As will be explained more fully hereinafter, iluid will besupplied to the upper end of cylinder 11 in proportion to the severityof the turn and, as the'lluid enters the bore 10, it will cause relativemovement between the piston 9 and cylinder 11. This movement has'fth'eeffect of moving the cylinder 11 and the frame lupwardly relative'tosuspension spring 6, thereby compensating for the dellection of theframe toward the outside spring suspension. Literally, the frame islifted relative to the spring suspension. However, with this arrangementthe suspension spring is fully operative at all times for its primaryfunction of absorbing road shocks and the like. It will be understoodthat as the vehicle comes out of the turn, the hydraulic uid will bedrained from the cylinder 11 and the parts 'will reass'rne their normalrunning position with the anged lvver end of the 'piston seated againstthe frame 1.

Referring now to Figure 4 of the dran/ings, I have therein illustrated acontrol system for the hydraulic cylinders which is formed as anintegral part of a conventional hydraulic steering system. As seen inthe drawings, the shaft 15 represents the mechanical steering connectionto the front Wheels, .the shaft being connected to the steering shaft 16by means of segment gear 17 and rack 18 which is threaded on the"steering' shaft. The steering shaft is rotated by measof steering Wheel19.

A conventional hydraulic stee' ng' assist is`V indicated at 20,hydraulic fluid being supplied fron-1 reservoir' 21 by means of pump 22.Conduits 22 and 23 are arranged to supply uid from the hydraulicsteering assist to opposite ends of a hydraulic assist cylinder 24having a piston 25. A piston' ro'd 26 projects from one end of theassist cylinder and carries a' rack 27 which `engages a segment gear 28fiXedly secured tothe shaft 15. With this arrangement, hydraulic fluidWill be fed to the cylinder 24- through either the conduit 22 or theconduit 23, depending upon the direction in which the steering wheel isturned, thereby causing the piston 25 to move Within the cylinder. Thevolume of hydraulic fluid supplied through either of the conduits willdepend upon the degree to which the steering vWheel has been turned, andthe piston 25 `vill be moved in proportion to the volume of fluidsupplied. Movement of the piston 25 causesl the vehicle wheels to turnas the shaft 15 is rocked by the action of rack 27 on pinion gear 28.For example, when making a left turn the parts Will be in the positionillustrated in Figure 4, and piston rod 26 and piston 25 will be movedto the left by fluid supplied to cylinder 24 through conduit 22. At thesame time iiuid Will be discharged from the opposite end of cylinder 24through conduit 23 for return to the' unit 20. The movement of piston 25and piston rod 26 will continue only so long as the steering Wheel isrotated', and when movement of the steering Wheel is stopped, themovement of the piston and piston rod will also stop and the parts willremain in the position established by' the steering wheel.

In accordance With my invention, the conduits 12R and 12L leading to thestabilizer control cylinders 11R .and 11L are connected t'o the conduits22l and 23, respectively, in substantially the manner illustrated'. Withthis arrangement, hydraulic fluid owing through either of the conduits22 or 23 will be divided between the assist cylinder 24 and one or theother of the stabilizer cylinders 11R, MAL. Thus, when making a leftturn, a por= tion of. the nuid flowing through conduit 22 will bediverted through. conduit 11R so as to' cause the piston 9R to move fromthe position illustrated in solid lines to the position illustrated indotted lines. As in thel case of piston 25,!the travel of the piston 9Rwill be directly proportional to the Volume of hydraulic fluid suppliedVto the stabilizer cylinder; and, as already indicated, the volume` offluid is directly proportional to Vthe severity or degree of theV turn.

From the foregoing, it Will-*be apparent that the auto= matic stabilizercontrol is directly operable from the hydraulic steering mechanism forthe vehicle. The quantity of hydraulic iiuid supplied to the stabilizercontrol cylinders is in proportion to the angular movement of theysteering Wheel and hence provides the proper degree ofbanking for anydegree of turn. When the steering wheel is in straight travel position,no fluid is supplied to the control cylinders, Whereas When the steeringWheel is turned full over, as for a left turn, the right stabilizercylinder 11R Will receive full uid charge to insure maximum banking ofthe vehicle. Similarly, for" every Cil angular position of the steeringwheel intermediate straight travel and full over positions, aproportionate quantity of uid is supplied to the stabilizer cylinders toprovide the proper degree of banking. It will be rcadily apparent thatfor a right turn, the flow of hydraulic uid will be through conduit 23to the opposite end of cylinder 24, with a portion ofthe uid flowingthrough conduit 12L to control cylinder 11L.

It is also within the scope o f my invention to provide a separatehydraulic Isystem for the stabilizer cylinder which is mechanicallycoupled to the hydraulic steering mechanism. Thus, as seen in Figure 3,a second piston rod 29 is connected to the rack 27 the last named pistonrod mounting a piston 30 slidablewithin a two-Way hydraulic cylinder 31.The piston 30 is normally centrally disposed within the cylinder 31 anda fluid reservoir 32 is arranged to communicate with the cylinder, thearrangement oi parts beingsuch that, when the piston is centrallydisposed, ports 33 and 34 are in communication with opposite ends of thecylinder and the uid 35 is free to flow between the reservoir and eitherend of cylinder 31. The mechanical connection between the rack 27 andpiston rod 29 is such that the piston 30 will be centrally disposed whenthe vehicle is traveling in a straight path. v

When the piston Sii is moved to the left in Figure 3, as would occurwhen the steering Wheel is turned so as to cause piston 25 in cylinder24 t o n'i'ov'e to the left, i.e. upon making a left turn, po'rt33 willbe closed and the iiuid in the cylinder31 ahead of the piston vvill bedriven through theconduit 12R connected to hydraulic stabilizercylinder' 11R. ItWill be apparent that movement of the piston 30 will inno Way affect the open condition of port 34 and hence there Will be nobuild-up of fluid in conduit 12L leading to control cylinder ilL. As thesteering gear of the vehicle is turned in the opposite direction tobring it out of the turn, the piston rod 29 will be moved to the right,thereby yreturning piston 3@ to its central position. This movementrecpens port 33 and vents conduit 12R, thereby permitting the piston instabilizer cylinder 11R to retract. It will be apparent that for a rightturn, the port 34 Will be closed with the resultant discharge of fluidfrom the cylinder 31 into the conduit 12L. With the arrangement instdescribed the necessity for dividing the hydraulic fluidbetvveen thestabilizer cylinders and the assist cylinder v24 is eliminated and therequired volume of fluid can be supplied directly from cylinder 31,thereby providing for independent adjustment of the' steering andstabilizing units.

With either of the foregoing control systems, it is preferred that thesystern be calibrated to raise the outer side of the vehicle slightlyhigher than the inner or turn side to improve the banking effect. Thus,should the vehicle be ina' left turn, it is preferred that the rightcontrolcylinder elevate the right side of the frame some- `u'lhat aboveits normal horizontal plane, thereby causing the vehicle body to bank inthe direction of the turn. When so operated, the control system' servesto improve the performance and handlingqualities of the vehicle Whentraveling in a curved path and, at the same time, full use is` made ofthe suspension springs for their intended purpose and at no time is thesuspension bypassedeither in' whole or in part.

Modifications may, uf course, be made in my vinvention withoutdepartingfrorn the spirit ofit. For example', While I have described myinvention as it applies to the knee action springing of the frontrunning gear, the invention also could be applied to the rear springsuspension if it were desired to further improve the corneringperformance of the vehicle.

Having thus described my invention in certain exemplary embodiments,what I desire' to secure and protect by Letters Patent is: y

1. In a; laankin'g` control device for a motor vehicle ivh'en travelingin a curved path, said vehicle having a frame, a wheel assembly and ahydraulic steering mechanism controlled by a steering wheel, asuspension spring connected to said wheel assembly and extending betweensaid wheel assembly and a banking control cylinder xedly mounted on saidframe, said cylinder having a piston to which said spring is operativelyconnected, whereby relative movement may be effected between said pistonand cylinder so as to effectively raise and lower said frame relative tosaid spring and said wheel assembly, said piston having a retractedposition in which the end of said suspension spring connected to saidpiston is effectively seated against said frame, said piston occupyingthe said retracted position when the vehicle is traveling in anessentially straight path, and a twoway control cylinder for supplyinghydraulic fluid to said banking control cylinder, said last namedcylinder having a piston therein operatively connected to the hydraulicsteering mechanism for said vehicle, said piston being movable withinsaid control cylinder upon turning movement of said steering wheel andeffective to supply uid to said banking control cylinder in proportionto the angular movement of said steering wheel.

2. The device claimed in claim l including a reservoir for supplyinghydraulic uid to said control cylinder, a port communicating betweensaid reservoir and said control cylinder, said port being closable uponmovement of said control cylinder piston in one direction.

3. The device claimed in claim 2 including a second port connecting saidreservoir and said control cylinder, said last named port being closableupon movement of said control cylinder piston in the opposite direction.

4. lIn an automatic banking control for a motor vehicle having a frame,a wheel assembly comprising upper and lower arms pivotally connected atone end to said frame and pivotally connected at their opposite ends toa steering knuckle, a spring retaining plate secured to said lower arm,a helical suspension spring supported at its lower end on said plate, ahydraulic cylinder mounted on said frame above said suspension spring,said cylinder including a normally retracted piston terminating beyondthe end of said cylinder in a projecting flange engaging the upper endof said suspension spring, said piston extending through an opening insaid frame with said projecting flange seated against said frame whensaid piston is in its retracted position, and means for supplyinghydraulic uid to the upper end of said cylinder, whereby to producerelative movement between said cylinder and said piston.

5. The structure claimed in claim 4 including a shock absorber extendingbetween said plate and said piston.

6. The structure claimed in claim 5 wherein said shock absorber lieswithin the contines of said suspension spring.

7. -In a stabilizing device for a motor vehicle when traveling in acurved path, said vehicle having a hydraulic steering system controlledby a steering wheel, a frame, and a wheel assembly separated from saidframe by a suspension spring, said device comprising a banking controlcylinder tixedly mounted on said frame, a piston for said cylinder, asuspension spring having one end thereof operatively connected to saidpiston and the opposite end thereof connected to the wheel assembly ofsaid vehicle, said piston having a retracted position in which the endof said suspension spring connected to said piston is effectively seatedagainst said frame, said piston occupying said retracted position whenthe vehicle is traveling in a straight path so that said spring actsdirectly between said frame and said wheel assembly and said bankingcontrol cylinder is not required to support said spring, and meansoperatively connected to said hydraulic steering system for supplyingiluid under pressure to said banking cylinder, the volume of said iluidbeing in proportion to the angular position of the steering wheel forsaid vehicle, whereby to effect relative movement between said bankingcylinder and said piston in direct proportion to the angular position ofthe steering wheel and thereby effect relative movement between saidframe and the lirst named end of said suspension spring.

8. 'Ihe stabilizing device claimed in claim 7 wherein the meansoperatively connected to said hydraulic steering system for supplyingliluid to said cylinder comprises a two-way control cylinder having apiston therein movable in proportion to the turning movement of saidsteering mechanism.

9. )In a banking control device for a motor vehicle having a frame and awheel assembly on each side of said frame, a suspension spring connectedto each of said wheel assemblies and extending between the saidassemblies and a banking control cylinder mounted on each side of saidframe, said cylinders each having a piston to which the coacting springis operatively connected, said pistons each having a retracted positionin which the end of the suspension spring connected to the coactingcontrol cylinder is etectively seated against said frame, said pistonsoccupying the said retracted position when the vehicle is traveling in astraight path so that the said springs act directly between said frameand said wheel assemblies and said control cylinders are not required tosupport said springs, a hydraulic steering system controlled by asteering wheel, and means operatively connected to said hydraulicsteering system for selectively injecting hydraulic tluid into one endof each of said banking control cylinders so as to eiect relativemovement between each such cylinder and the piston thereof, said lastnamed means comprising a two-way control cylinder elective, upon turningmovement of said steering mechanism, to supply Eluid to either of saidbanking control cylinders, depending upon the direction of turningmovement, in direct proportion to the angular position of the vehiclesteering wheel.

References Cited in the le of this patent UNITED STATES PATENTS2,110,809 Murphy Mar. 8, 1938 2,165,617 Pacs July 11, 1939 2,279,120Hurley Apr. 7, 1942 2,556,288 Milster June l2, 1951 2,650,108 BruceAllg. 25, 1953 2,743,941 Walker May 1, 1956 2,757,938 Crowder Aug. 7,1956 2,809,051 Jackson Oct. 8, 1957

